10.5 GPM – 16,000 PSI
Pressure regulating valve unloader type with zero setting on delivery line: at
gun closure the water flow is bypassed at low pressure maintaining also the
delivery line in low pressure. AISI 303 stainless-steel pressure regulating valve equipped Inlet, outlet and bypass ports.
Near total zero setting of the pressure in the delivery line at gun closure.
ADVANTAGES:
▪ Increased safety for the operator.
▪ Delivery hose are easy to control when the gun is closed.
▪ Less force needed to reopen the gun.
o At gun reopening, work pressure is reached gradually.
▪ Operators work less heavily.
▪ Easy starting if a gasoline or diesel engine is used.
o Reduced pressure loss and hardly dependent on flow rate.
o Great reliability.
o Easy maintenance.
This product is intended to be incorporated on a finished machine. This product is to be utilized with clean fresh water, even slightly additives with normal detergents. For use involving different or corrosive liquids, contact the PA Technical department. Appropriate filtration should be installed when using impure liquids. Choose the valve in line with the working data of the machine where to be installed (permissible pressure, maximum flow and rated temperature of the system). In any case, the pressure of the machine must not exceed the permissible pressure imprinted on the valve.
Attention. The VB40/1000 Zero valve is sensitive to water flow: at gun opening (water flow through the valve) the system goes into pressure, at gun closure (flow interruption) the system works at low pressure. For this reason, the VB40/1000 zero valve cannot be installed on systems that fit always weeping antifreeze systems. Instead, it can be installed on systems with antifreeze systems weeping at low pressure. In this case it is necessary to create in the bypass line a pressure higher than the pressure at which the antifreeze system becomes weeping.
OPERATIONS
The valve regulates the maximum pressure of the system by varying the flow discharged by the bypass. The adjustment is made by altering, by means of a piston, the position of a sphere which partially closes the bypass opening.
The valve is sensitive to water flow. At gun opening, the water flows through the valve which maintains the system in pressure. At gun
closure, the interruption of the flow provokes the complete aperture of the bypass which allows discharge of the flow at low pressure.
At gun closure, the special mechanism of zero setting patented by PA, which does not include a check valve, keeps in connection the delivery line and the bypass line, in that way permitting to lower the pressure all around the system and not only in the source line of the valve.
INSTALLATION
This accessory, on a system that produces hot water, must be fitted upstream to the heat generator. On a system that generates hot water, it is advisable to fit in accessories that limit the accidental increase of fluid temperature.
Do not install the valve on the pump head: secure the valve to the machine’s frame by means of fixing holes obtained on the body. In this way the valve is subject to less vibrations, reducing therefore the wearing of the internal parts. The hose from the pump to the valve must have a minimum length of about one meter. Always install a safety valve to protect the system.
If the nozzle wears out, the pressure decreases. To reset pressure back at work level, it is necessary to replace the worn nozzle.
When a new nozzle is fitted, re-setting of the system to its original working pressure is required.
PRESSURE ADJUSTMENT/SETTING
The desired working pressure must be adjusted while the system is in operation and the gun is opened. Adjust the pressure by adjusting the tension clockwise to increase pressure or unscrewing the adjustment nut, taking care to lock the threaded piston with a second wrench.
The operation is easier if the correct nozzle has been chosen.
Pressure is increased by screwing the adjustment nut. In case pressure does not increase despite screwing the nut, do not force, but check that the nozzle flow rate/pressure ratio is correct.
